croon vs incant

croon

verb
  • To hum or sing softly or in a sentimental manner. 

  • To make a continuous hollow moan, as cattle do when in pain. 

  • To say softly or gently 

  • To soothe by singing softly. 

noun
  • A soft or sentimental hum or song. 

incant

verb
  • To state solemnly, to chant. 

  • To recite an incantation. 

How often have the words croon and incant occurred in a corpus of books? (source: Google Ngram Viewer )